Question

Which of the following is correct for 2p-orbitals?
A) $n = 1,l = 2$
B) $n = 1,l = 0$
C) $n = 2,l = 0$
D) $n = 2,l = 1$

Answer 1

The n describes as the principal quantum number and the l describes as the azimuthal quantum number. One can calculate these two terms based on the shell number of 2p orbitals and by using their respective formulas.

Complete step by step answer:

1. First of all we will learn about the 2p-orbitals and the terms n and l which are given in options. The term n is used for the principal quantum number. The principal quantum number is the orbitals number. So, for the orbitals s, p, d, and f the value of n i.e. principal quantum number will be 1, 2, 3, and 4 respectively.
2. Now the term l stands for the azimuthal quantum number which is the quantum number for an atomic orbital which gives us the orbital angular momentum and also it describes the shape of the orbital.
3. To find out the azimuthal quantum number value i.e. l, the following formula is used,
   $l = n - 1$
   Where then is the value of shell number
4. Now as the 2p-orbital has shell number 2, we can say that the term value of n is equal to 2.
5. Now let us put the value of n in the formula of azimuthal quantum number and find out the value of l as below,
   $l = n - 1$
   By putting the value of $n = 2$,
   $l = 2 - 1$
   Now by doing the subtraction we get,
   $l = 1$
   Therefore, the value of l is equal to 1.
   Therefore, the terms $n = 2,l = 1$ are correct for 2p-orbitals which shows option D as the correct choice.

Note:
The principal quantum number and the azimuthal quantum number two sets among four which are used to describe the state of electrons and orbital shape. The azimuthal quantum number is also called orbital angular momentum and is denoted by a symbol $l$.